The present invention is directed to improve leak detection systems, and more particularly, automobile-based leak detection systems that utilize higher pressure vapor as deployed through the automobile's air induction system via a sealing mechanism that forms a secure interconnection that minimizes vapor leaks and pressure loss at the interface where such pressurized vapor is delivered to the automobile's air induction system using the automobile's own induction system ducting or hose.
Systems and methods for detecting leaks in internal combustion engine systems are well-known in the art. In this regard, leak detection systems are extensively used in engine diagnostic and maintenance procedures, and in particular can be utilized to find leaks in EVAP systems, valves, gaskets, hoses, vacuum lines and reservoirs, throttle bodies, EGR valves, air intake ducting, intake manifolds, and exhaust systems among others.
The detection of leaks is important insofar as most systems of the internal combustion automobile are designed to be completely sealed. To the extent leaks are present in these systems, a wide range of consequences can occur, including loss of performance, increased fuel consumption, and drivability complications.
Historically, vapor from leak detection systems (smoke machines) has been delivered into the automobile system under test at the standard EVAP test pressure of 12-14 inches of water column pressure (0.47 psi). The most common delivery method has typically been accomplished by pressing the tapered nozzle at the end of the smoke output hose of the leak detection device into an automobile's vacuum hose, brake booster line, or EVAP service port adaptor among others. To test automobile air intake ducting and air induction systems a common method has been to disconnect the air filter housing from the ducting and insert a hollow, elastomeric tapered cone (see, e.g., U.S. Pat. No. 5,753,800 issued to Gillum May 19, 1998, entitled SMOKE GENERATING APPARATUS FOR IN SITU EXHAUST LEAK DETECTION, the teachings of which are incorporated by reference) with a vapor pass-through hose into which is inserted the tapered nozzle at the end of the smoke output hose of the leak detection device.
Historical leak testing of the different automobile systems of naturally aspirated internal combustion engines at the low pressures used above has been quite effective and useful. One reason is that the maximum load on the air intake system of a naturally aspirated internal combustion engine is approximately 1 psi of vacuum at idle and load reduces thereafter. Test pressure (0.47 psi) at approximately half of maximum load (1 psi) is adequate to find leaks. While the interface between the leak detection device and the automobile system is quite rudimentary, the low pressures historically used above are very forgiving.
In an effort to gain more power using less fuel, automobile manufacturers are increasingly turning to a gas compressor used for forced induction or boosting the air induction system of internal combustion engines by utilizing mechanical superchargers, exhaust gas turbines, turbo chargers and multiple turbo chargers among others. The amount of boost or increased intake pressure can be 6-9 psi on the low end for smaller engines up to and exceeding 36-40 psi under full load for larger engines. Not only are the air induction system components of boosted engines under much greater pressure than naturally aspirated engines, there are typically many additional components such as a super charger or turbo charger(s), intercooler or air charge cooler, recirculation valve assembly, throttle housings, boost sensors and waste gates among others. Boosted engines also require much longer air induction ducting. On a engine with twin turbo chargers, there can be up to 23 feet of intake ducting/piping as compared to 3-7 feet in a naturally aspirated engine.
In this regard, the detection of leaks is critically important insofar as the air induction systems on boosted engines are built with very tight tolerances and are designed to be completely sealed to operate effectively. The complications from leaks in a boosted system are multiplied with the increased pressure and may have a much larger negative impact on the performance on longevity of the engine and its components.
Similarly, the ability to detect and locate leaks in the air induction systems of boosted engines has been extremely difficult for lack of an interface to introduce higher pressure vapor. The standard EVAP test pressure of 12-14 inches of water column pressure (0.47 psi) is insufficient when the system under test is under 12 to 80 times more pressure under full load.
In order to properly test for the presence of leaks, however, it is imperative that a source of pressurized test vapor be delivered into the air induction system of the engine being tested. To that end, it is well-known to generate pressurized vapor having a visual marker combined therewith that is operative to provide a visual indicator at the site where a leak is detected. Exemplary of such systems include the SMOKEPRO® leak detection system manufactured and marketed by Redline Detection, LLC of Placentia, Calif.
Despite the fact that such systems are well-known and extensively utilized, a significant problem still arises in the art as to how higher pressurized test gas can be delivered into the air induction system of an engine such that no pressure test vapor is lost at the interface where the test gas is introduced into the air induction system. Indeed, maintaining the pressure at the point of entry into the air induction system is particularly important when attempting to detect leaks in turbocharged and supercharged engines that operate at substantially higher pressure, which in turn requires leak detection tests be conducted at least equal or greater pressure in order to insure adequate testing; however, substantial problems arise in simply forming a secure, leak-proof interconnection at the interface between where the pressurized gases are introduced into the air induction system to be detected.
In this respect, to the extent there is any loss whatsoever in pressure of the test vapor at the point of entry into the air induction system, the ability to detect leaks is severely diminished, especially when it is necessary or desired to test at higher pressures, however, substantial risk of pressure loss at the point of entry is exceptionally high insofar as the induction hoses and ducts of the air induction systems for each automobile manufacturer are different, and radically different designs are frequently used for each major automobile manufacturer, which can even vary significantly between the various makes and models of a particular manufacturer. Any loss of pressure whatsoever at the interface negates the ability to perform a pressure decay or leak down test which is the only test that will confirm that the repair(s) have solved the leaking condition with absolute certainty. In this regard, such air induction systems typically utilize an air induction housing coupled to air induction ducting or hose wherein the interface between the two is unique to each manufacturer, if not specific for a particular make and model of automobile. Because of the unique interface design or footprint between the air induction housing and air induction ducting or hose coupled therewith, there has not heretofore been available any type of design or consideration that has been made to insure that when pressurized leak detection vapors are introduced into an air induction system, or more particularly the air induction system ducting or hose thereof, that a secure interconnection can be attained that substantially minimizes, if not completely eliminates, any possibility of leaks or loss of air pressure when pressurized leak detection vapor are introduced thereinto.
Although attempts have been made to form a more secure interconnection between a source of leak detection vapor and the air induction duct of an automobile's air induction system, such as those disclosed in pending U.S. patent application Ser. No. 12/426,465 filed Apr. 20, 2009 entitled ENGINE LEAK DETECTOR AND LEAK DETECTION METHOD, the teachings of which are expressly incorporated herein by reference, such systems do not take into account the unique structure of the air induction system ducting or hose of each particular manufacturer and instead rely upon simple clamping around or about an air induction ducting or hose without any consideration of the unique design of a particular air induction system. The existing device not only eliminates the ability to test critical ducting from the air filter housing to the intake piping, it also introduces additional ducting that can introduce leaks into the test. Accordingly, there is a substantial need in the art for a leak detection system and method, and more particularly a sealing device, mechanism or interface that can insure a custom interconnection or mating engagement with an air induction hose or duct of a specific car manufacturer that substantially reduces, if not eliminates, any possibility of a loss of pressurized leak detection vapor as introduced into such air induction system. There is likewise a need in the art for such a device or interface that is of extremely simple design, exceptionally easy to use and can be manufactured to be deployed with virtually all types of pressurized leak detection systems. There is still further need in the art for such a device or interface that can be designed for use with a specific make and model of automobile air induction system that further can be reutilized as many times as necessary and operative each time to form an exceedingly secure and leak-proof interconnection.